Apparatus for testing and segregating articles



Jan. 14, 1941. w \NWILCQX 2,228,901

APPARATUS FOR TESTING AND SEGREGATTNG ARTICLES Filed April 30, 193B 4Sheets-Sheet l INVENTOR Wilcox ATTORNEY Jan. 14, 1941. w. H. WILCOXAPPARATUS FOR TESTING AND SEGREGATING ARTICLES 4 Sheets-Sheet 2 FiledApril 30, 1938 INVENTOR Wff. Wilcox BY @,.-%mmz Y Jan. 14, 1941. w. H.WILCOX APPARATUS FOR TESTING AND SEGREGATING ARTICLES Filed April 30,1938 4 Sheets-Sheet 3 ATTORNEY Jan. 14, 1941.

w. H. WlLCOX 2,228,901

APPARATUS FOR TESTING AND SEGREGATING ARTICLES 4 Sheets-Sheet 4 FiledApril 30, 1938 Patented Jan. 14, 1941 UNITED STATES APPARATUS FORTESTING AND SEGREGATING ARTICLES William H. Wilcox, Stockton, Calif.,assignor to California Cedar Products Company, a corporation ofCalifornia Application April 30, 1938, Serial No. 205,286

6 Claim.

This invention relates generally to apparatus for testing andsegregating articles, and in particular the invention is directed toapparatus for testing and segregating wooden pencil slats.

In the pencil slat manufacturing industry, the relatively thin and flatpencil slats are impregnated with certain materials such as parrafin,stain, etc. Thereafter the processed slats are placed in a drying kilnto remove as much moisture content as possible, and for the reason thatsuch elimination of moisture content prevents undesirable warping of theslats, and facilitates milling of the same into pencils.

Heretofore in the industry no practical apparatus has been available fortesting each and every one ofthe slats for moisture content prior to theactual manufacture of pencils therefrom. The practice has been towithdraw samples from the kiln, and to then subject such samples tolaboratory tests. Such practice was not only inadequate, butimpractical, due to its inefficiency.

It is therefore the principal object of this invention to provide anovel apparatus for segregating pencil slats according to the relativeradio frequency conductivity or dielectric characteristics of suchslats; the invention being mainly intended for the segregation of pencilslats having a moisture content in excess of a predetermined allowableamount, and which slats have a greater degree of conductivity than therelatively drier slats which meet the required standard.

However, it is also my intention that the invention may be used forsegregating pencil slats according to constituent characteristics-etherthan moisture content-which affect the conductivity of the slats.

Another objective of the invention is to provide apparatus for thepurpose described which is relatively high speed in operation, and whichapparatus includes effective mechanical and electrical apparatus inunique combination, for the testing and selection of pencil slats andthe segregation of those slats selected.

A further object of the invention is to produce a simple and inexpensivedevice and yet one which will be exceedingly eflective for the purposefor which it is designed.

These objects I accomplish by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawings similar characters of reference indicate correspondingparts in the several views:

Figure 1 is a side elevation of the apparatus embodying the presentinvention, and showing the slat deflecting plate in normal position.

Figure 2 is an enlarged fragmentary elevation, partly in section, of thedevice, and particularly illustrating the slat deflecting and liftingplate 5 in lowered position to receive a slat.

Figure 3 is a similar view, but with the plate raised to normal positionafter deflection of a slat and placement of the same in the upwardlyextending by-pass channel.

Figure 4 is a cross-section on line 4-4 of Fig. 3.

Figure 5 is a fragmentary cross-section on line 5-5 of Fig. 2.

Figure 6 is a diagram of the circuits employed 15 in connection with themechanical apparatus.

Referring now more particularly to the characters of reference on thedrawings, the device comprises a rectangular upstanding frame includingsupporting legs I which support a pair 20 of relatively large outwardlyfacing channel irons or side beams 2 disposed in transversely spacedrelation, and at a relatively steep upward slope from one end to theother. Transversely extending shafts 3 and 4 are journaled between the25 side beams adjacent the upper and lower ends thereof respectively.Each shaft carries a pair of sprockets 5 fixed thereon in transverselyspaced relation and closely adjacent the side beams. These sprockets arespaced apart less 30 distance than the length of a pencil slat.

Endless link chains 6 engage with and extend between correspondingsprockets 5; the top reaches of the chains being disposed in a plane ashort distance below the plane of the upper edges 35 of the side beams2. Motor I mounted on the frame drives these chains with the upwardlysloping top reaches moving toward shaft 3; such drive being accomplishedthrough the medium of belt 8, which extends between the motor pulley 9and 40 a pulley l0 fixed on shaft 3 outwardly of one of the side beams.

A rectangular hopper II is mounted transversely on the side beams 2adjacent the lower ends of the upper reaches of chains 5, and pro- 4jects upwardly from said side beams at right angles; the hopper being ofa size to receive a stack of pencil slats S in face to face relation andtransversely of the pair of endless chains 6. The stack of slats in thehopper is supported with the lowermost slat in clearance relation abovethe pair of chains by means of a platform [2 mounted on the side beamsand disposed between 'said chains and slightly above the plane thereof.

The chains are provided at eiiually spaced longitudinal intervals withoutwardly projecting lugs l3, which engage the back edge of thelowermost slat in the hopper and shift such slat from the hopper withmovement of the chains. The front and back of the hopper terminate attheir lower ends above the plane of movement of the lugs to permitengagement of said lugs with the lowermost slat and escape of the slatfrom the hopper. Slats are fed to hopper II by means of a conventionalendless belt conveyor shown generally at ll.

Unless selected and segregated or by-passed by means of the apparatushereinafter described in detail, the slats S on conveyor chains 5 movealong with said chains until they reach the upper sprockets 5. Thereuponthe slats are discharged onto an endless carry-oil. or inspection belt,shown generally at 5; said belt being driven and extending horizontallyaway from shaft 3. A flexible and weighted hold-down unit l5 assuresproper disposition of the slats as they transfer from chains 8 toconveyor i5.

Some distance beyond the hopper II and intermediate the ends of theupper reaches of chains 3 is a pair of parallel metallic plates l1 andI5 respectively which is disposed between the upper reaches of chains 8,and spaced apart so that the slats carried by the chains may passtherebetween without restriction. The lower plates I1 is mounted inflxed position in connection with the side beams by suitable means,while the upper plate I8 is mounted in fully insulated and adjustablerelation on the frame, by means of a plurality of insulators is of highdielectric characteristics. Such insulators depend from a dielectrictransversely extending cross member 20 adjustably supported byupstanding bolts 2| secured on the upper flanges of the side beams 2.Longitudinally extending and relatively long guide shoes 22 aresupported by adjustable beam mounted bracket units 23, said shoesextending from a point adjacent the hopper H to a point beyond plates I1and i8. Such shoes engage the slats on chains 5 inwardly of butimmediately adjacent the chains and hold the slats in proper transverseposition thereon.

A transverse shaft 24 is journaled on the side beams above the upperreaches of the chains, and is provided with a rearwardly projecting,radially disposed slat deflecting plate 25, which tapers to its outerend as shown. This deflector plate 25 is of a width to permit movementthereof from a position in a substantially parallel plane above thereaches of chains 5, as shown in Fig. 2, to a downwardly slopingposition between the chains and in the path of slats thereon, as shownin Fig. 3. A radial arm 25 of metal is flxed on one end of shaft 24, anddepends outside the adjacent side beam 2; the lower end of the arm beingprovided with a metallic armature head 21 mounted on the side thereofopposite-shaft 3. Such a head is disposed for arm-holding engagementwith the core 28 of an opposed winding electro-magnet 29 mounted on theside beam ahead of said arm. Arm 25 and head 21 are in effect anarmature. An adjustable compression spring 30 is mounted on the sidebeam above the electro-magnet and cooperates with arm 26 urging the sameaway from the electro-magnet and into engagement-when free of saidelectro-magnet-with a three-point cam 3| fixed on the adjacent end ofshaft 3.

When arm-25 is held immovable by the electromagnet and in engagementwith the core thereof,

deflector plate 25 is clear of the passing slats, and when said arm isfree of the electro-magnet, the spring 30 and rotating three-point cam3| act to cause the plate 25 to recurringly and automatically raise andlower. The cam 3| is of such proportion relative to the'remainder of theassembly that the deflector plate 25 will lower, deflect, and raise eachpassing slat, unless the electro-magnet holds the arm 25 clear of cam3|, and which it normally does, as will hereinafter appear.

The points of the cam clear arm 25 only a short distance when the arm isheld immovable under the influence of the electro-magnet and inengagement with the core thereof; A lubricating wiper W is mounted onthe side beam adjacent the cam, and lubricates the same.

A by-pass channel assembly 32, for the reception of the slats deflectedand lifted byplate 25, is mounted in upstanding position on the sidebeams and with its open lower or receiving end disposed in position toreceive slats from the plate 25, which when raised swings into said openlower end of the channel assembly. To prevent retraction of the slatsfrom the channel, outwardly deflectible finger hooks 32 are mountedlongitudinally on the exterior of the channel sides, and project throughslots in the lower ends thereof; said hooks facing upwardly and engagingbeneath the end positions of each slat as moved into the channel bydeflector plate 25. A compression spring 34 engages the shank of eachhook and urges such hook inward into the channel and into the path ofslats lifted by plate 25. In the present instance, the outer portion ofthe channel levels off rear.- wardly to a substantially horizontalpositionyso as to relieve the slat weight which otherwise would bear onhooks 33, and also to facilitate removal of the by-passed or segregatedslats.

A three-contact commutator 35 is fixed on one end of shaft 4 outwardlyof the adjacent side beams. A carbon brush 36 mounted on a dielectricblock 31 adjacent the commutator cooperates with the latter for thepurpose hereinafter described. The commutator contacts are arrangedrelative to the cam 3| so that the brush 36 engages one of said contactsat substantially the same time that one of the points of cam 3| is in anarm-engaging position.

The electrical apparatus, which includes the electro-magnet 29 andcommutator 35, and which apparatus is used in combination with the abovedescribed mechanism, and the circuits for such electrical apparatus areshown diagrammatically in Figure 6, which will now be described:

The plates l1 and I8 heretofore described may be termed the selectorplates; the plate being grounded to the frame as at 33, while the plateI8, insulated from the frame, is connected by a relatively short wire 45to the grid input terminal ll of a variable oscillator circuit showndiagrammatically at 42. This oscillator is disposed within a case 43mounted on the frame as close to the selector plates as possible, so asto reduce the length of wire 40 and cut down radio frequency loss asmuch as possible. Another case 44 mounted below the side beams and onframe cross members encloses a power supply unit 45 of usual type, aswell as other portions of the electrical apparatus, which must beenclosed for protection. As the power supply unit is showndiagrammatically, it is, of course, to be understood that its circuit isgrounded where necessary to complete the illustrated circuits.

The pair of wires 44 supply filament current to the oscillator unit,while another wire "at approximately 400 volts D. C. carries an input orplate current for the oscillator. A milliammeter 40 is interposed inwire 41.

The electro-magnet 20 is provided with two windings 49 and 50 wound inopposition to each other; the winding 48 having 6000 ohms resistance,while winding 50 is of 3000 ohms resistance. Winding 50 is energized atall times from the power supply unit through the medium of wires 5! and52, the latter wire having a voltage dropping resistor 53 interposedtherein, whereby to reduce the power supply unit voltage toapproximately 200 volts. One end of winding 49 is connected with wire 52by another wire ",whlch likewise has a voltage dropping resistor Iinterposed therein. The other end of winding 49 is connected by wire 58to the carbon brush 30 which cooperates with commutator 3!. The wire 51,including a fixed condenser 58 and a fixed resistor 59, connects betweenwires 54 and I and provides a spark quencher which prevents commutatorsparking. A wire 80 extends from the commutator and connects with theplate SI of a grid glow tube 62. A wire 83 including a fixed resistor 54is connected to wire 60 and grounded at 65 and maintains the plate ii atground potential.

An output wire 66 from the grid of the oscillator unit 42 includes aninterposed fixed resistor 66a, and is connected with one side of avariable resistor 61 including a calibrated dial 68. This resistor 51 isof 30,000 ohms resistance and is grounded as at 89. The other side ofsuch resistor is connected by wire I0 with the grid Ii of the grid glowtube 62; such wire 10 having an interposed resistor 12. A wire I!including a condenser I4 is connected between wire 10 and ground 15, andprovides a radio frequency bypass. A pair of wires 16 supply current tothe filament ll of grid glow tube 52 from the power supply unit M5. Thelegends adjacent the resistances and condensers shown in Fig. 6 of thedrawings indicate the capacity of each.

Operation The operation of the above described mechanism and electricalapparatus, to effect a selection and segregation of pencil slats havingexcessive moisture content, is as follows:

The circuit of the variable oscillator unit 42 is balanced or biasedbefore the mechanism is placed in operation. At the same time the gridglow tube is biased by manipulation of calibrated dial 68, which effectsadjustment oi resistor 61; the tube being balanced to resist apredetermined potential charge, and when so balanced, no appreciablecurrent passes from the tube plate 6| through wire 60. As a result,winding 49 of electro-magnet 29 is normally de-energized, and as winding50 of the electro-magnet is always energized, arm 26 normally is held incontact with the core and plate 25 raised.

With the apparatus in such normal position,

the motor I is started and slats S fed intohop per I I from which saidslats are individually cafried along with the upper reaches of chains 4transversely thereof and longitudinally spaced a substantial distance bythe chain lugs l3. Thus, each slat is passed separately between selectorplates I1 and i8 and which plates are in effect an air gap condenser. Aslong as the slats passing between said plates are of normal moisturecontent, the segregating mechanism remains inactive for the reason thatthe radio frequency loss introduced into the circuit of the oscillatorunit with the passage of such slat is not sumcient to produce apotential charge of great enough intensity to overcome the resistivecapacity of resistor 81 as adjusted.

However, when a slat having a moisture content in excess of suchpredetermined normal amount passes between the selector plates l1 andII. sufllcient radio frequency loss is introduced to unbalance thecircuit of the oscillator unit 2 and produce a potential charge in wire00, which will feed through resistor 01 and through wire 10 to the gridll of the grid glow tube 82. Thereupon the grid II loses its balance andthe current flows from plate 6| through wire 00 to the commutator. Thegrid glow tube and associated circuit functioning as above may be termedan electronic contactor. As the commutator 35 rotates and brush itengages one of the commutator contacts, winding is energized throughwires 54 and 56. As winding 49 is opposed to winding 50, energization ofwinding 40 counteracts the effect of winding 50 and de-magnetizes thecore 28.

At such instant, one point of cam 3| has approached lever 26 as close aspossible, and as the core has been simultaneously de-magnetized, thelever under the influence of spring 30 swings free of said core andengages the cam with a minimum of Jar and noise. Thereupon, withcontinued rotation of the cam, arm 26 follows the cam. and plate 25lowers and deflects the moving slat which caused actuation of theselector apparatus in the manner above described. When the nextfollowing cam point engages the lever, the deflector plate raises andlifts the deflected slat into by-pass channel 32, where it is engaged bythe hooks 33 and held against rotation. Thereafter, until another slathaving excessive moisture content passes between the plates I I and IS,the selector plate 25 will remain in normal raised position. This is dueto the fact that an instant after the circuit for winding 49 is closedthrough said one commutator contact and the carbon brush, such circuitopens due to continued rotation of the commutator. With such opening ofsaid circuit, core 28 of the electro-magnet is again energized, and aslever 26 reapproaches the core 28 and comes within the magnetic fieldthereof, it is held against further movement with the cam. When thecircuit for winding 49 is opened as above, the balance of the grid glowtube is reestablished, and such balance will not be upset with resultantrecurrence of the slat segregating cycle when the next followingcommutator contact engages the carbon brush as no potential charge isbeing fed into wire 65 from the circuit of the oscillator unit.

The entire operation of the apparatus is carefully synchronized, so thatthe chains 6 can be driven/at relatively high speed and yet withoutdisrupting the proper segregation of selected slats. The timing is suchthat when a slat with too great moisture content passes between theselector plates, the selector apparatus will function and plate 25 lowerinto the path of and deflect such moving slat.

The milliammeter 48 indicates the amount of current passing to theoscillator unit and thus such meter serves as a visible indicator of thedielectric characteristics of slats passing between the selector plates,there being a known relation between the dielectric characteristics ofthe slats and the indicated current flowing through the meter. The meteris preferably mounted on the apparatus in a position readily visible tothe operator.

From the foregoing description it will be readily seen that I haveproduced such a device as substantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful anddesire to secure by Letters Patent is:

1. A device for selecting and segregating articles according to theirdielectric characteristics'ineluding an endless conveyor including ashaft at each end thereof, means to feed anticles onto the conveyor insingle file order, another shaft ex tending transversely across theconveyor above the same, a radial article deflector plate fixed on theshaft, a lever extending radially from one end of the shaft, a cam onthe end of one of said first named shaft and arranged to actuate saidlever and deflector plate, a bypass channel mounted above said plate toreceive deflected articles, and electrical apparatus responsive to thedielectric characteristics of the articles and including spaced elementsmounted ahead of said plate and between which elements the articlespass, and a normally energized electromagnet operative to hold saidlever out of the path of the cam; said electrical apparatus beingarranged to deenergize the electromagnet upon passage between theelements of an article having a dielectric variance in excess of apredetermined normal.

2. A device as in claim 1 in which said conveyor includes transverselyspaced chains and article engaging lugs extending outwardly from saidchains at equally spaced points in the length thereof; there being anarticle hold down shoe above the conveyor and extending from a pointahead of said elements to a termination therebeyond and at a pointadjacent but ahead of the deflector plate.

3. In a device for testing and segregating articles according to thedielectric characteristics thereof including a conveyor to receive andmove the articles in single file order, electrical apparatus mountedadjacent the conveyor and arranged to test each article for a dielectriccharacteristic, and normally inactive article segregat ing mechanismmounted adjacent the conveyor and beyond the electrical testingapparatus; said segregating mechanism including a driven rotary cam, alever adapted for actuation from said cam, a deflector plate actuated bysaid lever, means normally holding the lever out of but immediatelyadjacent the path of the high point of the cam, the plate then being outof the path of articles on the conveyor, means actuated from theelectrical testing apparatus to release the holding means, and othermeans to synchronize said release of the holding means with the nearestapproach of the high spot of the cam to the lever whereby to minimizejar when the lever engages the cam.

4. In a device for testing and segregating articles according to thedielectric characteristics thereof including a conveyor to receive andmove the articles in single file order, electrical apparatus mountedadjacent the conveyor and arranged to test each article for a dielectriccharacteristic, and normally inactive article segregating mechanismmounted adjacent the conveyor and beyond the electrical testingapparatus; said segregating mechanism including a driven rotary cam, a.lever adapted for actuation from said cam, a deflector plate actuated bysaid lever, means normally holding the lever out of but immediatelyadjacent the path of the high point of the cam, the plate then being outof the path of articles on the conveyor, electrical means actuated fromthe electrical testing apparatus to release the holding means, and adrivencommutator associated with the electrical releasing means andarranged to synchronize said release of the holding means with thenearest approach of the high spot of the cam to the lever whereby tominimize j'ar when the lever engages the cam.

5. In a device for testing and segregating arti cles according to thedielectric characteristics thereof including a conveyor to receive andmove the articles in a row, electrical apparatus mounted adjacent theconveyor and arranged to test each article for a dielectriccharacteristic and normally inactive article segregating mechanismmounted adjacent the conveyor and beyond the electrical testingapparatus; said segregating mechanism including a normally inactivearticle deflecting element, an actuating lever associated with saidelement, a driven rotary cam adapted to actuate said lever, meansnormally holding the lever out of but immediately adjacent the path ofthe high point of the cam; means operative from the electrical testingapparatus to release the holding means, and other means to synchronizesaid release of the holding means with the nearest approach of the highspot of the cam to the lever whereby to minimize jar when the leverengages the cam.

6. In a device for testing and segregating arti-' cles according to thedielectric characteristics thereof including a conveyor to receive andmove the articles in 'a row, electrical apparatus mounted adjacent theconveyor and arranged to test each article for a dielectriccharacteristic and normally inactive article segregating mechanismmounted adjacent the conveyor and beyond the electrical testingapparatus; said segregating mechanism including a normally inactivearticle deflecting element, an actuating lever associated with saidelement, a driven rotary cam adapted to actuate said lever, meansnormally holding the lever out of but immediately adjacent the path ofthe high point of the cam; electrical means operative from theelectrical testing apparatus to release the holding means, and a drivencommutator associated with the electrical releasing means and arrangedto synchronize said release of the holding means with the nearestapproach of the high spot of the cam to the lever whereby to minimizejar when the lever engages the cam.

WILLIAM H. WILCOX.

